The present invention relates to a braking roller for systems for cutting metal bands into strips.
There are known systems that carry out the longitudinal cutting of metal bands into a series of longitudinal strips that are afterward used for various transformations.
In these systems for the longitudinal cutting of metal bands into strips, which are more commonly known as xe2x80x9cslittersxe2x80x9d, it is essential that once cut, the strips obtained from the band correctly wind so as to prevent difficulties of both rewinding and of successive treatment.
For this purpose, a braking system of the same strips is provided before their winding into single rolls.
The braking system that is part of the system itself must guarantee a correct and even winding tension of the single strips. In fact, it must be possible to compensate the difference of speed that generates after possible differences of thickness between a strip and the other, since the transversal section of the initial band may not have an even thickness. In fact, it may be thinner at the longitudinal side edges with central swelling, or it may be thinner centrally starting from the thicker longitudinal edges.
Moreover, these differences of speed and optional braking systems must not damage the surface of the band being machined, that must be protected as much as possible.
For example, felt elements used as braking system are known, guided into containment housings, that are determined in engagement on the strips of the passing band through an underlying inflatable thrust element. Since such elements transversally arranged with respect to the band, or to the single strips, are standstill with respect to the band, they cause a rapid wear and in any case, they do not guarantee the respect of the band surface.
As an alternative, the rubber surface of braking rollersxe2x80x94called xe2x80x9cpresser rollersxe2x80x9dxe2x80x94acting on the band strips, has also been provided with a series of surface peripheral notches, transversal to the roller axis, thus creating a series of rubber teeth that may allow some possibilities of bending in the advancement direction of the strip, or in the opposite direction. Such xe2x80x9cfoldingxe2x80x9d or xe2x80x9cyieldingxe2x80x9d surface tooth should facilitate the adaptation to the speed of the single strip of the braking roller. In this way, there would be a suitable differentiated braking on the associated strips cut from the band.
Also this solution exhibits some limitations due to the minimum quantity of deformation that is possible to obtain due to the operation noise and to the regulation difficulties.
Purpose of the present invention is therefore that of realising a braking roller, called xe2x80x9cpresser rollerxe2x80x9d, for systems for cutting metal bands into strips, which should solve the above technical problems.
Another purpose is that of eliminating any possible difficulty of braking even in the presence of strong variations between the speeds of the different strips obtained from the cutting.
Another purpose is that of eliminating any possible defect that may arise on the surface of the strips due to the braking, so as to protect the surfaces of the same strips.
Another purpose is that of realising a braking roller for systems for cutting metal bands into strips that should be little expensive and easy to manufacture and operate, without problems of continuous adjustment or setting interventions.
These purposes according to the present invention are obtained by realizing a braking roller for systems for cutting metal bands into strips, comprising a rotating and motorized (21) shaft (20), with two support bearings (33) adapted to support end pins (22, 23), which are located within a central side surface (24), which carries a series of idle pulleys (25), axially held by two side containment flanges (27), wherein said central side surface (24) there is provided at least one recess (30) inside which there is arranged at least one inflatable element (29) above which there is arranged at least one wear element (34) that is made to abut inwards of each idle pulley (25).
Additional features are illustrated in the dependent claims.